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Chery A15 / 480 LHD model. Manual - part 143

Overhaul of the hydraulic power pump

---- Check if the hydraulic power pump is clogged. Replace it, if necessary.

---- Check if there is abnormal noise in the hydraulic power pump Replace it, if necessary.

----

Check if there is leakage in the hydraulic system.

Replace it, if necessary.

CHECK OF THE SEAL OF POWER STEERING SYSTEM

Please follow the below steps:

Turn the steering wheel quickly to the left and right limit position and keep it immovable,
which can make the internal system pressure reach the maximum. Please pay attention to
the stay time.

·Visual inspect if the steering flux control valve, rack seal, vane pump(power steering pump)

or oil tube connectors leakage. Replace the seal components, if necessary.

Check if the ATF oil of the oil reservoir is enough. If it is shortage, inspect if the seal of the
power steering system is available.

If all the rack & pinion in seal components of the power steering gear housing are not
available, the ATF oil may flows into the bellow housing. Therefore, disassemble the
steering gear and replace all the seal rings.

Check if there is leakage in the oil tube connector. If necessary, find out the cause and

reconnect it.

Oil pump flow test

During inspection, turn the steering wheel to the limit position and apply enough force on
the wheel to ensure that the control valve of the steering gear can function normally.

When the engine is idling and the oil temperature range is 50℃±5℃, measure the flux of
the fuel pump and compare the reading of the flow meter with the specified value.

Next, adjust the rotating speed of the engine to three times as much as the idling speed and
repeat the test mentioned above. If the flux of the fuel pump can not return to the original
position immediately, it also shows that the oil pump works abnormally which could lead
to the instant failure or the discontinuity of the power. If the value of the internal leakage is
larger than 1.2L/min, the steering gear should be repaired.

Precaution: All the tests should be carried out when the engine is hot.

CHECK AND REPLACEMENT OF THE HYDRAULIC POWER OIL

Check the hydraulic power oil

----Repeat turning the steering wheel from one

limit  position  to  another  when  the  engine
is  idling  in  order  to  increase  the
temperature  of  the  power  steering  oil  to
40~80

℃

----Check the oil volume left in the oil

reservoir, the oil surface should reach
“max” mark of the reservoir. When the oil
is not enough, please check there is no
leakage of all the parts, otherwise fill with
the oil to the “max”.

Precaution: It is recommended to use the special machine for vacuumizing the injection
when filling with the power steering oil. Otherwise (for example, when the vehicle is
repaired). The specifications for filling the power steering oil and exhausting are shown
below: fill the oil reservoir with the power steering oil to the maximal position first, and
then start the engine at low speed (idling) to drive the steering pump so as the steering
system is full of the hydraulic oil. The engine must be kept in idling status to drive the
vane pump during refueling and meanwhile refueling continuously to avoid inhaling the
air of by the vane due to the fall of the oil level.

Replace the hydraulic power oil

---- Lift the vehicle to discharge the oil left in the oil reservoir and backflow hose.

---- Keep the engine idling, discharge the oil and meanwhile turn the steering wheel to the

end position until there is no hydraulic oil left.

Precaution: All these steps should be finished as soon as possible to avoid damaging the

hydraulic power pump.

---- Add the power steering oil.

---- Discharge the air completely in the hydraulic system.

EXHUAST OF THE STEERING HYDRALIC SYSTEM

---- Check the oil level. Fill with the oil, if necessary.

It should be exhausted as the hydraulic oil in the oil reservoir is emulsionized or the noise

of the pump is extremely loud (generally the maximal is 80 dbs) .The steps are shown
below:

Lift the vehicle, start the engine and turn the steering wheel left and right to the limit
position (Precaution: Do not keep stay on the limit position. If necessary, keep it less than

10 seconds). Repeat this step for several times to discharge all the air of the system from
the oil reservoir. Add the hydraulic oil as the oil level descends.

---- Keep the engine idling, repeat turning the steering wheel from the left limit position to

the right until there is no air bubble and foam in the oil reservoir. If the oil level
descends, fill with the oil to the specified value (max).

---- The exhaust of this type of vehicle is not easy. Please completely discharge the air bubble

left in the system. Otherwise, it would make the abnormal noise in the hydraulic power
pump.

CHECK OF THE OUTPUT PRESSURE OF POWER STEERING PUMP

The main purpose of checking the output pressure of the power steering pump is to determine
whether there  is  malfunction  in  the  power steering pump  or the steering  pinion  mechanism.
Before  checking,  in  order  to  measure  the  output  oil  pressure  of  the  power  steering  pump
accurately, the oil  level of the oil reservoir should reach the  normal position and the tension
of the drive belt of the power steering pump should conform to the standard.

Measure the output oil pressure of the power steering pump with the pressure gauge which is
connected in series with a manual valve in the system. When the engine stopped, remove the
pressure  pipeline  from  the  power  steering  pump, connect  an end  of the  pressure gauge  with
the connector of the pump outlet, join another end of the  manual valve with the  inlet nozzle
of  the  steering  control  valve,  so  the  pressure  gauge  and  the  manual  valve  are  connected  in
series in the pressure pipeline of the power steering pump and steering control valve.

Steps for measuring the output oil pressure of the power steering pump are shown below:

---- Open the manual valve completely.

---- Start the engine and keep it idling.

---- Repeat turning the steering wheel from the left limit position to the right for several times

until the steering oil temperature reaches 80

and

℃

ensure that the oil level normal.

---- Measure the static oil pressure at the rotating speed is 800r/min. The reading of the

pressure gauge is at least 300kPa if the power steering pump functions properly.

---- Close the manual valve gradually until the pointer of the pressure gauge keeps stable and

get the reading. At that time, the output standard pressure of the power steering pump
should be at least 6.2~6.9MPa; The small reading of the pressure gauge shows that
pressure of the steering pump is too low which can not effectively complete the steering.
That means there are malfunctions in the steering power pump and therefore it should be
repaired or replaced.

CHECK OF THE TENSION OF THE BELT

If there is wear, crack or flake on the belt, please replace it in time. For checking the tension,
moderate pressure should be applied in the middle of the pulley by thumb and the
displacement of the belt should be about 10mm. If the belt is too slack, please go to the
nearby service station of Chery to adjust and repair it.

DIAGNOSIS AND TROUBLESHOOTING OF POWER STEERING

SYSTEM

The  frequent  malfunctions  of  the  hydraulic  power  steering  system  are  the  oil  leakage,
infiltration  of  air,  failure  of  the  power  steering  pump,  and  damage  of  the  steering  control
valve and mechanical transmission mechanism of the hydraulic transmission mechanism. All
these  malfunctions  show  in  different  forms,  such  as  steering  heavily,  noise,  unsmoothness,
vibration and so on. When the power steering system is in trouble, please diagnose the failure
and eliminate it at once.

Steering heavily

※Malfunction symptom

In general, the steering should be easy for a vehicle with power steering system. If it fails, the
steering would be heavy and the steering wheel would be hard to turn.

※Malfunction reason

Generally, it is caused by the invalidation or the insufficient power of the hydraulic power
steering system; Damage or improper adjustment of the mechanical transmission mechanism.
The specific reasons are shown below:

The oil reservoir leakage or oil level is lower than the specified value.

The oil tube connectors is not well sealed, leakage always happens.

The air enters the steering hydraulic loop.

The oil tube is deformed; Oil pipeline is blocked; oil pressure or flux of the oil pump is
insufficient.

The tension of the power steering pump driving-belt is insufficient and the belt slides.

The wear and leakage in the steering pump are serious, which makes the output pressure of
the oil pump lower than the standard.

·The pressure regulator oil pump fails, and the output pressure is too low.

There is internal leakage in the steering control valve and power hydraulic cylinder

The steering pinion mechanism is damaged or adjusted improperly, steering link system
components are bended, and friction force on every ball pin is too large.

The tire pressure is too low.

Front wheel alignment is not accurate.

The vehicle is overloaded seriously.

※Diagnosis and Troubleshooting

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